Stop an already scheduled nstimer

Question

I am starting a timer to trigger an event based on a false condition.However if the condition becomes true within the scheduled time, i need to stop the event from triggering.

if(!condition)
{
  myTimer =[NSTimer scheduledTimerWithTimeInterval:200 target:self selector:@selector(trigger:) userInfo:nil repeats:NO];
}
else
{
 if([myTimer isvalid])
   [myTimer invalidate]
   myTimer= nil;
}

If condition becomes true within 200 sec don't trigger the @selector.

Invalidating the timer doesn't stop the method from triggering. I can do this by having a BOOL flag, but can i do it using NSTimer's methods.

Answer 1

You must be creating multiple instance of myTimer. Check whether myTimer already initailized or not ?

if(!condition)
{
  if(myTimer == nil)
     myTimer =[NSTimer scheduledTimerWithTimeInterval:200 target:self selector:@selector(trigger:) userInfo:nil repeats:NO];
}
else
{
 if([myTimer isvalid])
   { 
     [myTimer invalidate]
      myTimer = nil;
    }
}